Electrical coil



April 11, 1939. FRANZ 2,154,070

ELECTRICAL COIL Filed Jul 16, 1956 2 Sneets-Sheet 2 IN VEN r01?E.E.FRANZ ATTORNEY Patented Apr. 11, 1939 UNITED STATES PATENT OFFICEELECTRICAL ooIL Application July 16, 1936, Serial No. 90,874

3 Claims.

This invention relates to electrical coils and more particularly tocoils in which the winding is tapped at one or more intermediate pointswhereby a'portion only of the winding may be energized if desired.

An object of the present invention is to provide a tapped coil in whichthe taps brought out to a surface of the coil structure are constructedin a simple and reliable manner and with minimum addition to the bulk ofthe structure and disturbance of the windings.

In one embodiment of the invention, there is contemplated a coilcomprising a plurality of superimposed layers of windings of aninsulated l6 electrical conductor in which taps are brought up from oneor more intermediate turns of the winding to extend beyond one end ofthe body of the winding, the taps being-either loops of the windingitself or conductive members secured to the winding and extending acrossthe turns thereof, and these taps being simultaneously held in placeamong the turns of the winding and insulated therefrom by means oflaminar members coated with adhesive material.

Other objects and features of the invention will appear from thefollowing detailed description of two embodiments thereof taken inconnection with the accompanying drawings in which the same referencenumerals are applied to identical parts in the several figures and inwhich Fig. 1 is a view in front elevation of a coil constructed inaccordance with the invention;

Fig. 2 is an end elevation thereof;

Fig. 3 is a plan view thereof;

Fig. 4 is a broken sectional view on the line 4 4 of Fig. 3;

Fig. 5 is a section on the line 55 of Fig 2;

Fig 6 is a perspective of a detached tap member;

Fig 7 is a detached diagrammatic perspective view of the incompletewinding only of a modified form of coil, and

Fig 8 is a detached view of a portion of the winding of Fig. '7 with aclamp in place thereon.

In the embodiment disclosed in Figs. 1 to 6 inclusive, a coil has amagnetic core 20 of any approved material and construction, here shownas an H-shaped mass which may be thought of as silicon steel. Around thecross-bar of the H may be a protective wrapping 2| of any suit-ablematerial such as paper or cloth with or without an impregnation ofvarnish, shellac, or the like; although in some instances this wrapping2| may be omitted if desired.

Over the wrapped or naked cross-bar is a winding 22 of insulatedelectrical conductor. The conductor may be thought of as'a copper wirewith an insulating coating, e. g. enamel, textile threads, felted fibresof paper stock or of asbestos or any other suitable material applied to5 the wire in any appropriate manner. The conductor is wound on the corein regular superimposed layers of snugly abutted coils and between eachtwo oonsecutive layers of coils may be a wrapping 23 of material such asthat of the 10 wrapping 2i; although the wrappings 23 ma be omitted insome instances if desired. /1 The conductor is wound on coil by coil andlayer on layer until a point is reached at which a certain desired andpredetermined length of conductor or number of turns has been put inplace, and at which point it is desired to bring out a tap. Under thelast turn and over the surface of the previous turns is placed a stripor flexible lamina 24 of insulating material coated, preferably on bothsides, with a suitable adhesive, e. g. a strip of tough paper coatedwith rubber cement, a piece of electricians tape, or the like. Upon thisadhesive insulating lamina is placed a tap member 25in the form of astrip of sheet metal perforated at its upper end as at 26 for subsequentconnection purposes. A supply of such strips 25 may be preparedbeforehand all of identical form and dimensions. Then when one is to beplaced in position it is given a single transverse offset 21 at thepoint along its length where it is to be crossed by the particular turnof the winding to which it is to be attached. This offset mayconveniently be done with a pair of pliers either plain or havingcorrespondingly shaped offset jaw surfaces.

The tap member 25 having been placed in position on the adhesive strip24, the turn of the winding to be connected to the tap is denuded ofinsulation at the point where it crosses the tap and is then preferablysoldered to the tap as indicated at 28. vA second adhesive insulatinglamina 29 similar to 24 is then pressed over the tap arid the coils andthe winding is continued until a point is reached where it is desired tohave another tap. The above procedure is then repeated.

-Tap members thus placed are rigidin themselves and are rigidly held inplace by the combined effect of the adhesive laminae 24 and 29 and ofthe subjacent and superjacent turns of the windings. They are easilymaintained in position after being placed and during the subsequentwinding; and are not easily displaced after the coil is completed. Beingrelatively rigid in themselves, they may be made tov occupy relativelyaccurately predeterminable positions relative to each other and to theouter contours of the finished coil, thus rendering the coil so madesusceptible of simple predeterminable mounting in relation to otherelectrical apparatus to be associated therewith. Also, such taps may berugged in themselves and so well adapted for subsequent permanentcombination with other apparatus by means of soldered connections.

While it is preferable to have the laminae 24 and 29 of or coated withadhesive material, it is in some cases suflicient if they are merelysoft enough for the tap and wire to embed themselves therein.

Of the embodiment shown in Figs. 7 and 8 there is disclosed only thedetached and incomplete winding, this being thought sufllcient toillustrate this form of the invention. Here the winding 22 is made asbefore by winding an insulated conductor in consecutive superimposedlayers of closely abutted coils or turns until a point is reached atwhich it is desired to have a tap. The wire of the winding is here bentout at right angles to the surface of the coil as indicated in dottedlines in Fig. 'I and carried out to the distance required. It is thendoubled back on itself and again bent at right angles to extend alongthe direction of continued winding. Where the two right angled bends inthe wire abut against each other at the base of the loop I25 thusformed, the two parts of the wire are secured together, e. g., by beingwhipped with one or more turns of non-conductive strand or of wire, orby having some clamping means applied. Apreferred form of such means isdisclosed in Figs. 7 and 8. This is a blunt pointed, triangular bit 30of malleable sheet metal, 'e g.', soft galvanized sheet iron, appliedflat against the two wire angles and then having two of its corners 3|and 32 folded over the apices of the angles and its third corner 33folded down over these two.

An adhesive insulating lamina 24 is pasted over the preceding windings,the loop I2! is brought up into'the full line position of Fig. 7,

and a second adhesive insulating lamina 29 is' pasted over the loop H5.The winding is then continued and other taps may be taken oi! in thesame fashion at other suitable points. At the outer end of each tap I25,the wire may be denuded for a short distance to provide a connectingterminal as.

It will be evident that the embodiments herein disclosed areillustrative only and may be modifled and departed from in many wayswithout departing from the spirit and scope of the invention as pointedout in and limited only by the appended claims.

What is claimed is:

1. In an electrical coil having means to support a winding and aplurality of turns of conductor strand forming a layer of winding on thewinding supporting means, a lamina of insulating material adhesive onboth sides and extending over and in contact with a portion only of theturns of the layer, a turn of the layer extending over the lamina incontact therewith,

a tap member connected to the last named turn and extending over thelamina in contact therewith, a second lamina of insulating materialadhesive on both sides and extending over and in contact with the firstlamina and the last named turn and the tap member, and a second portionof the turns of the layer extending over and in contact with the secondlamina, the parts being so disposed and proportioned that each of thelaminae is over some of the, turns of the tapped layer and under somethereof and the tapped turn and the tap member are substantiallyimmovably held between the two laminae and insulated thereby from theremainder of the coil.

2. In an electrical coil having means to support a winding ands.plurality of turns of conductor'strand forming a. layer of winding onthe winding su porting means, a lamina of insulating material adhesiveon both sides and extending over and in contact with a portion only ofthe turnsof the layer, a turn of the layer extending over the lamina incontact therewith, a tap member connected to the last named turn andextending over the lamina in contact therewith, a second lamina ofinsulating material adhesive on both sides and extending over and incontact with the first lamina and the last named turn and the tapmember, and a second portion of the turns of the layer extending overand'in contact with the second lamina, the tap member consisting of astrip of metal having an oiIset therein to receive the turn connectedthereto, the parts being so disposed and proportioned that each of thelaminae is over some of the turns of the tapped layer and under .some

thereof and the tapped turn and the tap member are substantiallyimmovably held between the two laminae and insulated from the rest ofthe coil thereby.

3., In an electrical coil having means to support a winding and aplurality of turns of con ductor strand forming a layer of winding onthe winding supporting means, a lamina of insulating -material adhesiveon both sides and extending ,ver and in contact with a portion only ofthe turns of the layer, a turn of the layer extending over the lamina incontact therewith, a tap member connected to the'last named turn andextending over the lamina in contact therewith, a second lamina ofinsulating material adhesive on both sides extending over and in contactwith the first lamina and the last named turnand the tap member, and asecond portion 01 the turns of the layer extending over and in contactwith the second lamina, the tap member comprising a loop of theconductor strand extending from the lastnamed turn and held in form byclamping means at the base thereof, the parts being so disposed andproportioned that each of the laminae is over some of the turns of thetapped layer and under some thereof and the tapped turn and the tapmember and the clamping means are substantially immovably held "betweenthe two laminae and insulated from the remainder of the coil thereby.

IRWIN E. FRANZ.

